Vibrant Blue Cavansite on Stilbite from India - Extinct Pune Mines - Extremely Rare Mineral Specimen - Height: 130 mm - Width: 80 mm- 365 g - (1)

Specimen with captivating spheres of Cavansite on Stilbite matrix — This specimen of notable mineralogical interest presents a rare and fascinating association of Cavansite and Stilbite, hydrated calcium, vanadium, silicate and aluminum-silicate minerals respectively. The crystal formation develops on a basaltic matrix typical of the Deccan Traps, a geologic region renowned for its exceptional zeolitic mineralization. Cavansite manifests in spherulitic aggregates, while Stilbite forms distinct tabular crystals that contribute to a complex and visually rich texture. Chromatically, the specimen is dominated by the pearly-white and milky appearance of Stilbite crystals, which exhibit a vitreous-pearly luster and good transparency in some areas. In stark contrast and with harmonious distribution, Cavansite spheres emerge, characterized by an intense bright blue-green color, often described as 'peacock blue' or 'indigo blue', standing vividly against the lighter background. The matrix consists of porous basaltic rock, ochre-brown in color, providing solid support and an authentic geological context to the mineral association. The provenance of this lot is Maharashtra, India, a classic locality of primary importance for zeolitic minerals and associated species. The volcanic formations of the Deccan Traps have created geodes rich in hydrothermal solutions, ideal for the precipitation of minerals like Cavansite and Stilbite. Cavansite crystallization often occurred in successive stages after Stilbite, forming crusts or nuclei on it, as observed in this piece. The aesthetic of this specimen is excellent, with uniform coverage and good density of Stilbite and Cavansite crystals distributed over the surface. The Cavansite spherules are well formed and retain their distinctive color, while Stilbite crystals are intact and display their typical grain-like or tabular crystal habits. The overall composition of the piece is balanced and offers a striking visual impact for any collector. The condition is rated as good, with the main crystals well preserved. Minor imperfections or separations are minimal and consistent with the fragile nature of these minerals and mining methods. The specimen is well suited for display in a mineral cabinet, enhancing its intrinsic beauty and rarity. It is not mounted on an artificial base, allowing full appreciation of its natural form. This specific lot represents an opportunity to acquire a classic Cavansite and Stilbite specimen from India, a highly sought-after association in mineral collecting. The combination of vivid colors, clear definition of crystal forms, and provenance from a reference locality make it a desirable piece for both experienced collectors and enthusiasts in search of iconic specimens.